低温等离子体技术改性填料前后Anammox工艺运行及微生物群落变化

Variation of operating and microbial community of Anammox process with convertional and modified filler by low temperature plasma technology

采用低温等离子体技术对普通聚氨酯泡沫塑料填料进行表面改性处理,研究了改性前后填料的表面特征、厌氧氨氧化生物膜量、脱氮性能、微生物群落结构及其功能微生物基因丰度的变化。结果表明:低温等离子体改性以后填料表面与蒸馏水的静态接触角减少33.27°,单点比表面积和吸附平均孔径分别由8.98 m^2·g^-1和3.01 nm提高至9.66 m^2·g^-1和4.98 nm,材料表面粗糙度增加,亲水性能明显改善;未改性单位质量填料生物膜干质量为0.18 g,改性后单位质量填料生物膜干质量为0.37 g,相同时间内单位质量填料上的生物膜量相比于填料改性前提高了53%;填料改性前后系统总氮去除率均在80%以上。高通量测序结果显示,2系统菌群结构相似,主要功能菌属是Candidatus Kuenenia,改性填料相比于未改性填料其微生物种类丰富程度更高。实时荧光定量PCR(qPCR)结果显示,改性后hzo基因相对丰度由59.50%增至73.50%,提高了14%,nxrB基因相对丰度由21.10%减至17.70%,降低了3%。由此可见,填料经改性后表面生物膜量增加,生物膜上功能微生物种类丰富性也有所增加,但在较低氮基质负荷条件下脱氮效率基本不变。

The conventional polyurethane foam plastic carrier was modified by low temperature plasma technology.The variations of surface physicochemical properties,anaerobic ammonium oxidation(Anammox)biofilm quantity,nitrogen removal performance,microbial community structure and functional microbial gene abundance of conventional and modified filler were investigated.The results showed that the static contact angle between the surface of modified filler and distilled water decreased by 33.27°compared with conventional filler,single point specific surface area and adsorption average pore diameter of modified filler increased from8.98 m^2·g^-1 and 3.01 nm to 9.66 m^2·g^-1 and 4.98 nm,respectively.As a result,the surface roughness of modified filler increased,and its hydrophily improved obviously.The biomass on the conventional filler was 0.18 g,while the biomass on the modified filler was 0.37 g,over the same period,the biomass on per mass filler increased by53%,therefore the biofilm formation rate improved obviously.For both the conventional and modified filler,the total nitrogen removal rates maintained over 80%.Furthermore,Illumina Mi Seq sequencing indicated that Candidatus Kuenenia was the dominant bacterial genus in the biofilm on the conventional and modified filler.Compared with the conventional filler,the biofilm on the modified filler had a higher microbial species diversity.Quantitative real-time PCR(q PCR)showed that the hzo gene abundance increased by 14%from59.50%to 73.50%,while the nxr B gene decreased by 3%from 21.10%to 17.70%.It could be concluded that the biofilm quantity on the modified filler increased,and the richness of functional microbial improved,however,the nitrogen removal efficiency presented slight change under low nitrogen influent loading condition.